# git rev-parse -q --verify eb8257a12192f43ffd41bd90932c39dade958042^{commit} eb8257a12192f43ffd41bd90932c39dade958042 already have revision, skipping fetch # git checkout -q -f -B kisskb eb8257a12192f43ffd41bd90932c39dade958042 # git clean -qxdf # < git log -1 # commit eb8257a12192f43ffd41bd90932c39dade958042 # Author: Mahesh Salgaonkar # Date: Mon Sep 20 22:03:26 2021 +0530 # # pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init # # On pseries LPAR when an empty slot is assigned to partition OR in single # LPAR mode, kdump kernel crashes during issuing PHB reset. # # In the kdump scenario, we traverse all PHBs and issue reset using the # pe_config_addr of the first child device present under each PHB. However # the code assumes that none of the PHB slots can be empty and uses # list_first_entry() to get the first child device under the PHB. Since # list_first_entry() expects the list to be non-empty, it returns an # invalid pci_dn entry and ends up accessing NULL phb pointer under # pci_dn->phb causing kdump kernel crash. # # This patch fixes the below kdump kernel crash by skipping empty slots: # # audit: initializing netlink subsys (disabled) # thermal_sys: Registered thermal governor 'fair_share' # thermal_sys: Registered thermal governor 'step_wise' # cpuidle: using governor menu # pstore: Registered nvram as persistent store backend # Issue PHB reset ... # audit: type=2000 audit(1631267818.000:1): state=initialized audit_enabled=0 res=1 # BUG: Kernel NULL pointer dereference on read at 0x00000268 # Faulting instruction address: 0xc000000008101fb0 # Oops: Kernel access of bad area, sig: 7 [#1] # LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries # Modules linked in: # CPU: 7 PID: 1 Comm: swapper/7 Not tainted 5.14.0 #1 # NIP: c000000008101fb0 LR: c000000009284ccc CTR: c000000008029d70 # REGS: c00000001161b840 TRAP: 0300 Not tainted (5.14.0) # MSR: 8000000002009033 CR: 28000224 XER: 20040002 # CFAR: c000000008101f0c DAR: 0000000000000268 DSISR: 00080000 IRQMASK: 0 # ... # NIP pseries_eeh_get_pe_config_addr+0x100/0x1b0 # LR __machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350 # Call Trace: # 0xc00000001161bb80 (unreliable) # __machine_initcall_pseries_eeh_pseries_init+0x2cc/0x350 # do_one_initcall+0x60/0x2d0 # kernel_init_freeable+0x350/0x3f8 # kernel_init+0x3c/0x17c # ret_from_kernel_thread+0x5c/0x64 # # Fixes: 5a090f7c363fd ("powerpc/pseries: PCIE PHB reset") # Signed-off-by: Mahesh Salgaonkar # [mpe: Tweak wording and trim oops] # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/163215558252.413351.8600189949820258982.stgit@jupiter # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux-ld --version # < git log --format=%s --max-count=1 eb8257a12192f43ffd41bd90932c39dade958042 # < make -s -j 32 ARCH=arm64 O=/kisskb/build/powerpc-fixes_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux- defconfig # < make -s -j 32 ARCH=arm64 O=/kisskb/build/powerpc-fixes_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux- help # make -s -j 32 ARCH=arm64 O=/kisskb/build/powerpc-fixes_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux- olddefconfig # make -s -j 32 ARCH=arm64 O=/kisskb/build/powerpc-fixes_arm64-defconfig_arm64-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/aarch64-linux/bin/aarch64-linux- /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2711-rpi-4-b.dts:220.10-231.4: Warning (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format error, expected "0,0" /kisskb/src/scripts/dtc/include-prefixes/arm/bcm2711-rpi-4-b.dts:220.10-231.4: Warning (pci_device_reg): /scb/pcie@7d500000/pci@1,0: PCI unit address format error, expected "0,0" /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi:464.3-52: Warning (pci_device_reg): /pcie@f8000000/pcie@0,0:reg: PCI reg address is not configuration space /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi:464.3-52: Warning (pci_device_reg): /pcie@f8000000/pcie@0,0:reg: PCI reg address is not configuration space /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi:464.3-52: Warning (pci_device_reg): /pcie@f8000000/pcie@0,0:reg: PCI reg address is not configuration space /kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi:464.3-52: Warning (pci_device_reg): /pcie@f8000000/pcie@0,0:reg: PCI reg address is not configuration space /kisskb/src/arch/arm64/kvm/hyp/nvhe/Makefile:58: FORCE prerequisite is missing Completed OK # rm -rf /kisskb/build/powerpc-fixes_arm64-defconfig_arm64-gcc11 # Build took: 0:08:31.201643